Coking apparatus



A. H. SCHUTTE COKING APPARATUS Nov. 3, 1953 Filed March 10, 1951 INVENTOR I .flqgwz fiizlym ATTOR Patented Nov. 3, 1953 UNITED STATES PATENT OFFICE August H. Schutte, Hastings-on-the-Hudson', N. Y.,.. assi'gnor to- The. Lummus' Company, New York, N; Y., a corporation of Delaware ApplicationMarch; I0, 1951, SeriirPNo: 214';948

5 Claims. 1

This invention relates to the continuous conversion. of liquidhydrocarbon to coke and vaporous. material in the presence of a continuously moving". gravity packed column of coke particles which serve to supply the required heat for the reaction and become coated with the residual carbon, the vaporousmaterials being separately withdrawn for further treating as desired. It is a specific improvement on the apparatus shown in copending application Serial No. 3,747, filed January 22,1948 now Patent N 0. 2,561,334, issued July 24, 195.1, of which I ama co-inventor.

It has been. pointed out that the use of moving columns of gravity packed granular material serve as an excellent heat transfer medium for carrying out various physical and chemical conversions. Such systems can be and are being used for catalytic reactions particularly in vapor phase operations; The liquid phase operation raises a further complication. however, for it is indispensible to most reactions that a uniform charge be given a uniform heat treatment. It is important that deviationsfrom the average temperature at any one region be avoided. and every effort is made to have the contact material move through. the reactionzone at a uniform rate.

My present invention isprimarily concerned with a unique flow control apparatus and the method of drying the coke particles to more effectively obtain a continuous coking operation;

Another principal. object of my invention is. to-

provide an improved apparatus for continuous coking of heavy hydrocarbon oils, such apparatus beingeasily controlled, simple in construction, and relatively small in comparison to structures heretofore available.

Further objects and advantages of my invention will appear from the following'description of a preferred form of embodiment thereof, taken in connection. with the attached drawing in which:

Fig. 1 is an elevational view with parts insection of a continuous coking apparatus.

Fig. 2 is a detailed central vertical section. of the lower part of a reactor and as more specificallytaken on the line 2-2-'of Fig. 1.

Fig. 3 is a horizontal cross section taken on the line 33' of Fig. l.

' The continuous coking cycle in accordance: with the invention disclosed in Patent No. 2,561,334 above noted, includes a pre-heating of granular petroleum coke particles as ultimately made in the system, such particles being fed to a reactor H) from hopper 12 by gravity through line 14. The heavy hydrocarbon charge primarily in liquid phase is applied to this hot coke by feeding the H) as more specifically" shown in Fig. 2.

liquid: through conduit m to one or more feed nozzles I8 which distribute the oil on the: coke before it reaches the main body of the reactor L0 The reactor 12B: is preferably of such depth and: the: particles contain sufiicient. heat: so that the applied liquidv will go to dryness before the particles are: drawn off. at 2-0. At leastfive" min.- utescoketravel: time and asmuch as forty minutes may be necessary between the. fuel? injection and coke draw or: points based on several; factors hereinafter described: in. order that: the coke: may be removedv in a dry unagglomerated condition. Thehydrocarbon' vapors are removed at 2 2:.

In order to supply the heat requirem'entsin the reactor the" coke particles. are. passed. through a reheater 2 in whichzther particles may'be'suitably heated by fuel gas and: air entering. at 26 or by partial combustion. the coke is usually heated therein to about 1000: to 1G50 F. The products of combustiorrare removed at 28;

The reheated. coke particles are next passed alternatively through pressuredrums so and 32' suitably controlled by inlet valves 34c. and 34b and by outlet valves-"36a. and 3&2) and thence-into theblowscase-ut. By'suitable controls not shown, a: minimum particle: level. can. be maintained in blow case 38 and with the application of a gas or steam lifting medium through line Ema constant flow of particles can be obtained through. lift line Discharge is into vapor separator M from which. the heated particles continuously flow by gravity into-hopper !:2-- through line 45 to'compl'ete the: cycle.

It will be: understood that various flow: control I elements. valves and; regulators will be used. In

general, a. circulation. of one hundred tons per hour oi granular cokeof from 40' mesh to inch average particle size will be suffioient. to reduce about. 1060 barrels per day oi: a. 10 API reduced crude having a Conradson carbon content of 1.3%. The not make of coke will be drawn off at 5!! or other suitablelocation.

A particular feature of my present invention is the bottom: draw off for solids in the reactor Conveniently and preferably, the bottom Ida is conical shaped: having an angle of about 45 with the vertical. Within this section I provide a series of vertical splitter plates 52 and as shown in Fig. 3, I provide increasing numbers of plates as the cross section increases. In the lowermost bank for example twelve are used. In the next higher bank, twenty-four will be used and in the higher banks, the number will be correspondingly greater. Generally, I find three banks sufiicient in addition to the bank at the draw off pipe which of course establish the uniform draw off characteristics of the entire column.

Surmounting these splitter plates 52 is an inverted cone 54 which may in turn support the vapor draw off assembly. This includes a central pipe 56 in communication through slots 56a with the lateral vapor outlet 22. A vapor collecting cone 58 is mounted above the central pipe 20.

The lower cone thus produces an annular flow to the splitter plates 52. The flow is then subdivided by the splitter plates into independent Streams which uniformly supply the draw off pipe 20 which is of sufficient length to diameter ratio so that the solids velocity is essentially constant throughout its cross section. The total flow is throttled by valve 59 in said draw ofi pipe.

Under certain conditions it is found that the cone 58 will support a conical mass of particles thereabove i. e. that it will not draw particles from the entire cross-section of the bed and that a central static zone may be formed. This can be eliminated by concentrically superposing a second frusto-conical baffle plate 65 on the cone 58. The distance between the two cones is adequate to insure the flow of particles therebetween, usually at least 6 to 8 particle diameters. By this means it is possible to insure a positive flow and to prevent any dead spaces in the vessel above the cone 58.

I may also use a grid of radial rods 60 to further subdivide the column of particles and to prevent the passage of any particle which would cause jamming in the outlet 20. These rods 60 may be mounted on the concentric grid of rods BI and the steam sparger pipe 62. The steam sparger is fed by steam inlet 64 and serves to dry out the coke below the vapor draw off.

It has been my experience that the vapor outlet 22 is most effective when it is not more than A; and preferably of the distance between the feed inlet and the particle draw ofi, above the outlet. Not only do I obtain adequate time for conversion of the liquid charge to vapors and dry coke, but I can also obtain an essentially vaporfree steam stripping zone below the vapor draw off during which I obtain complete drying with the aid of steam introduced at 64.

The steam from the stripping zone serves to seal the reactor against egress of oil vapors with the coke thru draw oiI pipe 20. In passing up thru the stripping zone the steam becomes highly superheated by heat transfer with the coke and, upon entering draw off cone 58 and mingling with the oil vapors from the upper reactor, this steam prevents dew-point condensation of heavy ends and resulting coking of the vapor drawofi system.

While I have shown and described a preferred form of embodiment of my invention, I am aware that modifications may be made thereto which are within the scope and spirit of the disclosure herein and of the claims appended hereto.

I claim:

1. In an elongated vertical vessel having a granular particle inlet conduit at the upper part and a conical bottom portion and a granular particle outlet conduit communicating therewith the combination of flow control means in said the baflies are surmounted by a, radial and annular grid the cross sectional openings of which are not larger than the opening in the outlet conduit.

3. Apparatus for effecting the conversion of a fluid reactant in the presence of a particle form solid contact mass material flowing as a downwardly moving column which apparatus comprises a cylindrical reaction chamber, reactant inlet and distributing means at the upper part of the chamber for introducing reactants into said reaction chamber, reaction product outlet means at a lower part of the chamber for Withdrawing reaction products therefrom, a solid contact materia1 inlet at the upper part of said reaction chamber, said chamber having a conical bottom portion and an outlet conduit extending from said bottom portion for discharge of solid contact material therefrom, said conical bottom portion and said outlet conduit having a plurality of uniformly spaced inwardly extending vertically disposed bafiies, said baffles being in increasing number with the increasing diameter of the bottom portion of the chamber whereby they subdivide the horizontal cross section of the conical bottom portion into relatively uniform horizontal areas, and a solid central member surmounting the bafiles to establish annular flow from the chamber through the baflled areas.

4. Apparatus as claimed in claim 3 in which the reaction product withdrawal means is about A; the distance from the reactant inlet means to the solid contact material outlet, above the outlet.

5. Apparatus as claimed in claim 4 in which a steam sparger is mounted on the baffles and below the reactant outlet whereby the steam atmosphere aids in sealing the particle flow against loss of reactant vapors and reduces the tendency of coke formation in the vapor outlet.

AUGUST H. SCHUTTE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 778,301 Burdick Dec. 27, 1904 1,784,650 Adams Dec. 9, 1930 2,393,893 Evans et a1 Jan. 29, 1946 2,430,669 Crowley Nov. 11, 1947 2,432,344 Sinclair Dec. 9, 1947 2,482,138 Schutte Sept. 20, 1949 2,494,695 Fisher Jan. 17, 1950 2,511,813 Lockwood June 13, 1950 2,526,701 Shirk Oct. 24, 1950 2,568,239 Lonngren Sept. 18, 1951 2,596,610 Shabaker May 13, 1952 

1. IN AN ELONGATED VERTICAL VESSELL HAVING A GRANULAR PARTICLE INLET CONDUIT AT THE UPPER PART AND A CONICAL BOTTOM PORTION AND A GRANULAR PARTICLE OUTLET CONDUIT COMMINICATING THEREWITH THE COMBINATION OF FLOW CONTROL MEANS IN SAID CONICAL BOTTOM PORTION, SAID FLOW CONTROL MEANS INCLUDING A PLURALITY OF UNIFORMLY SPACED, RADIALLY EXTENDING SHALLOW BAFFLES PROJETING VERTICALLY FROM SAID CONICAL BOTTOM PORTION INTO THE PATH OF FLOW OF SAID GRANULAR PARTICLES TO SUBDIVIDE THE FLOW INT A PLURALITY OF VERTICAL STREAMS, SAID BAFFLES BEING IN BANKS OF INCREASING NUMBERS WITH THE INCREASING DIAMETER OF THE BOTTOM PORTION OF THE VESSEL, AND A CENTRAL MEMBER SURMOUNTING THE BAFFLES TO ESTABLISH ANNULAR FLOW FROM THE VESSEL THROUGH THE BAFFLED AREAS. 